Compact fixation devices of the above-mentioned type, for example, that of the fixed type described in Italian Patent No. 1,183,736 and that of the articulated type described in U.S. Pat. No. 4,604,997, are known.
These known minisplint devices effectively perform the task required of them but are susceptible of some improvements.
In fact, both the minisplint devices mentioned above have at least one clamp which can move with respect to a longitudinal support by means of an adjustment screw in which the screw is axially immobilized with respect to the by a washer which is retained by one recessed end or by means of a locking pin. However these immobilizing systems have little strength in the axial direction, and can deform or break very easily, and also show excessive play.
Secondly, the clamps have only two seats for the bone bolts which are located symmetrically with respect to a tightening screw, with a minimum distance which may be excessive for small bones, and which in any event is not always an optimum distance.
Furthermore, the opposing half-cylindrical seats formed by the clamps only make it possible to securely hold bolts or Kirschner wires of a single diameter.
Another disadvantage lies in the limitation of the effective travel of the movable clamp due to the fact that the slide of the latter cannot run to the end of the longitudinal guide groove.
Finally, in the case of an articulated clamp, the rotating joint has a fixed limb which is of excessive size on the side of the securing head, and therefore a different device must be used for mounting on each side of the bone. Finally, the relative angle formed between the two parts connected by the joint is adjusted manually and approximately, and not micrometrically.